1. Field of the Invention
This application contains subject matter that is related to the subject matter of co-pending U.S. patent application Ser. No. 11/048,458, filed Jan. 31, 2005. The aforementioned related patent application is herein incorporated by reference.
The present invention is generally related to backup storage systems and, more particularly, to a method and apparatus for efficiently generating backup files.
2. Description of the Related Art
To provide data redundancy and security within a computer network, information stored in a server connected to the network is backed up to a storage system on a periodic basis. Generally, a plurality of servers are connected to a backup server. The backup server serves as a primary component in a storage management system whereby timing and control of the backup processes are performed by the backup server. Periodically, information stored in the servers is copied to the backup server. The backup server generally stores the information within a mass storage system or device.
Backup files typically utilize the MICROSOFT Tape Format (MTF). To prepare a file using this format, the backup software retrieves each file that is to be backed up and adds header information. The header information is appended to the beginning of the file along with security information to form an overhead portion of a backup file. Each file to be backed up is added to the backup file with its associated overhead portion until all of the files have their overhead and the file concatenated into the backup file. Such a backup file is provided with an extension entitled. “bkf”.
When a set of files is backed up in this matter, the set of files in the .bkf file is referred to as a backup set. Upon the initialization of a backup process, the first backup set is generally a full backup that copies each and every file that is to be backed up into the backup file. Thereafter, incremental backups can be performed to backup only files that are changed with respect to the full backup. These incremental file backups occur on a periodic basis. Each incremental backup creates another backup set. Over time, the backup server will store the full backup as well as each of the incremental backups.
A synthetic full backup can be created using a full backup and subsequent incremental backups. The synthetic full backup is a file that contains the data of a full backup without actually performing a full backup procedure, i.e., copying all the files of a server. The synthetic full backup is formed by copying the original full backup and all the incremental backups to a new .bkf file. This new .bkf file is the synthetic backup. This file can now be used as a full backup with respect to subsequent incremental backups. The creation of synthetic backups is time consuming and requires a substantial amount of storage to enable the various data copies to be used.
If the data is to be restored to the server that was backed up, a synthetic full backup can be copied to the server to restore all of the data that would have otherwise been lost from a server crash or other malfunction.
Therefore, there is a need in the art for an improved process for generating backup files.